Difference between a Gene and an Allele
What is a Gene?
A gene is a unit of heredity that determines the characteristics or traits of an organism. Each gene is made up of a sequence of DNA, which provides instructions for the development and functioning of the organism. Genes are found on chromosomes, which are long, coiled-up strands of DNA that are located in the nucleus of cells.
What is an Allele?
An allele is a variant form of a gene. Each gene can have multiple alleles which give different versions of the same trait. For instance, if we consider a gene that governs eye color, it may have alleles for blue eyes, green eyes, brown eyes, and so on. Alleles can be dominant or recessive, meaning that one version of the gene may overshadow or mask the other.
The Key Difference between Genes and Alleles
The main difference between genes and alleles is that genes are the basic units of heredity, whereas alleles are the different forms of genes that arise due to mutations or genetic variation. Genes are present in all cells of an organism, whereas alleles can be specific to a particular trait, and may only be expressed in certain cells or tissues.
In terms of inheritance, an individual inherits two copies of each gene, one from each parent. In the case of alleles, an individual may inherit two copies of the same allele, which is called homozygous, or different alleles, which is called heterozygous.
Conclusion
In summary, genes and alleles are both important parts of genetics and provide the basis for inheritance and variation. Understanding the difference between the two can help us better comprehend how traits are passed down from parents to offspring and how genetic disorders can arise due to mutations or changes in gene expression.
Table difference between a gene and an allele
| Aspect | Gene | Allele |
|---|---|---|
| Definition | A segment of DNA that codes for a specific protein or RNA molecule | A variant form of a gene |
| Location | On a specific locus on a chromosome | On the same locus as the original gene |
| Function | Codes for a particular trait or characteristic | May result in a different version of the same trait or characteristic |
| Number per individual | Two copies of the gene (one inherited from each parent) | May have multiple alleles, but an individual can only have two (one from each parent) |
| Examples | The gene for eye color | An allele of the eye color gene, such as blue or brown |